Tuning and push button control



5 Sheets-Sheet 1 D. H. MILLS TUNING AND PUSH BUTTON CONTROL April 4,1950 Filed Dec. '7, 1945 INVENTOR.

April 4,1950 D. H. MILLS 2,503,121

TUNING AND PUSH BUTTON CONTROL Filed Dec. '7, 1945 5 Sheets-Sheet 2 N mW M I' mm! N I Hull IN IN V EN TOR.

April 4, 1950 0.1-1. MILLS TUNING AND PUSH BUTTON CONTROL Filed Dec. 7,1945 5 Sheets-Sheet 3 Z5 INVENTOR.

April 4, 1950 D. H. MILLS TUNING AND PUSH BUTTON CONTROL 5 Sheets-Sheet4 Filed Dec. 7, 1945 INVENTOR.

April 4, 1950 D. H. MILLS 2,503,121

TUNING AND PUSH BUTTON CONTROL Filed Dec. 7, 1945 5 Sheets-Sheet 5Patented Apr. 4, 1950 TUNING AND PUSH BUTTON CONTROL Donald H. Mills,Fort Wayne, Ind., assignor to The Magnavox Company, Fort Wayne, Ind., a

corporation of Delaware Application December 7, 1945, Serial No. 633,471

. 9 Claims.

The present invention relates to radio tuning devices and moreparticularly to a radio tuning device provided with a plurality of pushbutton actuators for moving the tuning device to selected predeterminedpositions. Heretofore push button actuated tuners of the type moving thetun-' ing element to a predetermined position had the disadvantage ofnot providing a sufiiciently large number of push buttons thus limitingthe selection of stations to be received by push button operation. Incertain of the pushbutton tuning devices, which generally utilize avariable capacitor or tuning condenser, the tuning device has beensubject to displacement after it has been moved to a predeterminedposition by a push button due to vibration and the like. It, therefore,would be desirable to provide some arrangement whereby the tendency fora tuning device to shift is minimized.

The push button tuners of the type moving an element to a predeterminedposition have generally been provided with a manual driving control. Inorder to provide for easy actuation of the push buttons, it has not beenpossible to provide anything but a relatively low ratio of drive betweenthe manual tuning control and variable tuning device. Any attempt tointroduce a relatively high ratio between the tuning control and thetuning device increased difficulty of moving the push buttons to such anextent as to make the arrangement relatively unfeasible. In view of thefact that the forthcoming radio receivers will operate not only in thebroadcast band, but also in the high frequency FM band, it is desirableto provide a larger number of push buttons and an extended dial tofacilitate the indication in tuning in the higher frequency ranges.

It is an object of my invention to provide, in a manually controlledpush button tuning device of the. cable driven type, means for afiordinga relatively high ratio between the tuning control and the shaft of thetuning device, and at the same time, prevent a back pressure load on themovement of the push buttons.

It is a further object to provide in a tuning device means forautomatically disconnecting the push buttons upon their initial movementfrom the tuning control means, thus greatly reducing the pressurerequired to actuate the push buttons.

It is a further object of the present invention to provide an improvedpush button tuning device which minimizes the wear on the pointer cableand provides smoother operation of both the push buttons and the manualtuning control.

A still further object of the'present invention is to provide animproved push button tuning device having a larger number of pushbuttons for the same linear dimensions.

A still further object of the present invention is to provide animproved tuningdevice having an extended dial scale provided with aninherently light pointer having a smooth travel.

Other and further objects of the present invention subsequently willbecome apparant by reference'to the following description taken inconnection with the accompanying drawings wherein Figure 1 is a frontview of the tuning device embodying the present invention with portionsthereof broken away to show a part of the tuning drive mechanism; I

Figure 2 is a plan view of a tuning device shown in Figure 1; v

Figure 3 is a right end view of the tuning device shown in Figures 1 and2;

Figure 4 is a top view showing certain details of the tuning drivemechanism associated with the manual tuning control;

Figure 5 is another view similar to Figure 4 illustrating anotherposition or condition of operation;

Figure 6 is a perspective view ofthe treadle bar of the tuning deviceand .the various cables and pulleys of the manual tuning control and thedial indicator; v

Figure 7 is a perspective view of the manual tuning control disengaginglevers Figure 8 is a right end view as seen in the direction of thearrows along the line 8-8 of Figure 2;

Figur 9 is a view similar to that shown in Figure 8 illustratin theoperation of one of the push buttons; and

Figure 10 is an exploded view of the elements comprising a single pushbutton actuator.

Referring to the drawings there is shown in Figure 1 the mounting basell of a radio chassis having a vertically extending upright panelportion l2. The front panel portion I2 has an aperture l3 through whicha plurality of push button and push button levers extend. The front ofthe panel may be provided with control nobs such as the manual tunincontrol knob l4 and a volume control knob [5. A plurality of push buttons I 6 arranged in two horizontal rows with pairs of push buttonsaligned vertically extend forwardly of the upright panel l2.

Mounted upon the base I I of the radio receiver chassis is a variabletuning condenser or capacitor l1 having a plurality of stators l8 and aplurality of rotors I9. Th rotors I!) are mounted on a common shaft 2|and are secured to a wheel or pulley 22. The wheel or pulley 22 isprovided with a cable 23 which is passed around a smaller pulley 24. Thesmaller pulley 24 is supported from a shaft 25 carried by a bracket 26secured to one end plate of the gang condenser IT. The shaft 25 alsocarries a pulley 2'! which is engage by a cabl 23. The cable 28 passesover two pulleys 29 and 3| mounted on the back side of the upright panel|2 so that the cable moves horizontally in the proximity of a guide rail32 having a pointer 33 which cooperates with the longitudinal tuningdial 34. After passing over the pulleys 29 and 3| the cable 28 passesover a pulley 35 mounted on the front panel l2 so that the cable iscontiguous to a portion of the manual tunin control shaft 38. The cable28 after leaving the pulley 35 passes over an adler pulley 31 and backto the wheel 21.

The cable arrangement described is also illustrated in perspective inFigure 6. By referring to Figure 6 and also Figures 3, 4, and 5 it willbe seen that the cable 28 as it passes the manual tuning control shaft38 is adapted to be contiguous to a roller ortion 38 which may be formedon the shaft 36'. Preferably the roller portion 38' is of a materialwhich will provide a high coefiicient of'frictio'n between th roller 88and the cable 28. Such roller for example may comprise a rubber sleevesecurely bonded to the shaft 38.

Mounted on the frontpanel i2 is a lever 39' which is shown with greaterparticularity in Figure '7 The lever 39 adjacent the top is providedwith an aperture 4| whereby the lever may be pivotally mounted on thepanel l2. At an intermediate point the lever 88 is provided with anaperture 42 which is adapted to receive a pinor' stud arranged to passthrough an aperture 43 in another lever 44. The lever 39 adjacent itslower extremity i provided with an aperture 45 which is adapted to serveas a journal for one end of a shaft 48. The other end of the shaft 45 ismounted in a bracket 47. The shaft 45 at an intermediate point isprovided with an idler wheel or roller 48 having a sufficiently highcoefficient offriction, and side flanges 49 to cause it tocooperatefirmly with roller 38 and cable 28 at its side flanges 49 which engagethe roller 38 as may be seen from Figure 4.

The lever 39" has a lower depending extremity 58 which is adapted to beengaged by a rearwardly extending projection 5| formed on the lever 44.The lever 44 is pivotally secured to the lever 38 in such manner as toprovide a certain degree of friction there between. The. lever 44 at itslower extremity is provided with a projection 52 which is adapted to beengaged by a spring 53 and a cable or cord 5 One extremity of the spring53 as may be seen from Figure l is secured to either the chassis base Hor the edgeof the front panel l2. The cord or cable 54 passes over apulley 55 secured to the base I! as may be' seen from Figure 2 whereuponthe cable or cord continues on to a treadle. bar 56. The-treadle bar 58is provided with pivotal supports 51 suitably journalled in the endplates of the variable tuning device or condenser The spring 53 whichengages the projection 52 of the lever 44 causes the, forward projection5| of that lever to engage the depending projection 58 of the lever 39so that normally the idler wheel 48 is in engagement with the roller 38and the. cable 28 asis seen from Figure 4.

The cable and pulley arrangement interconnecting the shaft 2| of thevariable tuning capacitor with the shaft 38 of the manual tuning controlprovides a relatively high ratio drive between these two shafts. Thusfor example a relatively high ratio 16 to 1 may be obtained so as toreadily permit minute manual adjustment of the tuning capacitor which isparticularly suited for tuning a radio receiver in the higher frequencyranges. Due to the fact that the idler wheel 48 is arranged normally toengage the cable 28, and the flanges l9 are of slightly greater diameterthan the body of the wheel 48 there is assured a high degree offrictional contact between the cable 28 and the pulley 38 and the wheel48'.v

Reference may now be had to Figures 1, 2, and 8 to 10, which illustratethe push button mechanism for moving the condenser rotor topredetermined selected positions. The condenser shaft 2| carries aplurality of plate members 58 which support a pair of cam followermembers or bars 59 adapted to be engaged by any one of a plurality ofcam members carried by the levers connected to the push button It. Aswas previously stated the push buttons it are arranged in two horizontalrows with pairs of push buttons aligned vertically. This arrangement ismore particularly illustrated in Figures 8' and 9 wherein the upper andlower push buttons l8 are connected to actuating members 8| and 82. Themembers BI and 62 are of similar shape and are reversed in position forthe upper and lower positions l8; Each of the members 5| and 82therefore is connected toa similar push button tuning mechanism shown inthe exploded view of Figure 10. The forward portion of the member 82 isprovided with a reduced end portion 83 upon which a lower push button Itmay be frictionally secured. The member 62 has an intermediate upwardlybent portion 84 which is connected to a terminating bifur cated portion55. The bifurcated portion is adapted to be spot welded to a camsupporting member 65. The cam supporting member has a forwardlyextending portion 6'! which is provided with a slot 68 and a frontportion 68 bearing an aperture 1|. The slot 88' has a transverselyarranged recess l2 for receiving a nut member I3 secured to a screw M.The screw 14 is mounted in an aperture H' of the forwardly extendingportion 81 of the cam supporting member 88. The nut member i3 is alsoengaged by a locking member 15 which is formed in two similar portions78 and i1 interconnected by a pair of strap members 18. The lowerextremities of the portions l6 and 11 are provided with slots orapertures 79 and 8| for receiving the nut member 13. Each of the membersit and 1': adjacent its upper portion is provided with an aperture 82adapted to receive a pin which passes through an aperture 83 in theupper portion of the cam supporting member 55. The cam supporting memberEfisupports an arcuate cam 84 having two forwardly extending camsurfaces 85 and 88 adapted to engage the two transversely arrangedcambars 59 on opposite sides of the tuning condenser shaft 2|. The rivet orpin 8? which passes throughthe apertures 82 and 33 in the members 8-8and 75 also supports a springv 88 having right-angled end portions 89and 5|. The one extremity 88 is adapted to engage a notch 92 on the backside of the member 68, and the other extremity 91 is adapted to bepositioned between the connecing bars 78' of the member 15 so as toengage the inner arcuate surface 93 of the cam member 84. The spring 88therefore serves to retain the cam 84 so that its outer arcuate surface94 is incontact with the concave arcuate surface 95 of the member 66.

The tuning device of the condenser adjacent its one side is providedwith an upwardly extending plate 96 having a plurality of apertures 90best seen in Figure 1 which receive the forwardly extending portion 61of the cam supporting members 66. The cam supporting members 66 are eachprovided with a forwardly extending portion 91 which passes throughsuitable openings in the transversely arranged bar 98 shown in Figures 8and 9. The bar 98 extends between the end plates of the condenserslightly in front of the stators I8. Thus the cam actuator mechanismsare arranged for reciprocable motion by being supported by the members96 and 98. Adjacent the forwardly extending portion 91 of the member 66there is provided an aperture 99 which is engaged by a spring IOI havingits other-extremity engaging the upright wall portion 96. The springsIOI therefore bias the push button I6 forwardly so as to return the pushbutton immediately after actuation. The forwardly extending portions 91of the cam supportin member 66 when actuated engage the treadle 56 whichas may be seen from Figure 8 normally is positioned but a very shortdistance in front of the extremity of each of the members 91. Thus uponthe initial portion of the movement of any push button I6, the treadlebar 56 is actuated. This causes the treadle bar to pull on the cable 54against the action of the spring 53. This moves the lever 44 whichfrictionally engages the lever 39 so as to displace the wheel! to aposition shown in Figure 5. This disengages the cable 28 from the roller38 so that whenever any push button is actuated, the cable 28 does notdrive the manual tuning control shaft 36. This provides relatively freeactuation of the tuning ele- 4 ment and the cable which supports thepointer 33 thereby minimizing the effort required to tune the radioreceiver and minimizing the wear on the parts associated with the tuningelement. As soon as the push button has moved the rotors of the tuningelement to a selected predetermined position the treadle 56 is returnedto its former position thus again causing the cable 28 to be engaged bythe wheel 48 and the rollers 38. Since there is such a high gear ratiobetween the movement of the pulley 48, the roller 38 and the cable 28,this provides a force which resists any movement of the tuning elementfrom its predetermined position due to such forces as for examplevibration.

In order to preset each of the push button actuators, there is removedfrom the front of the radio set an escutcheon I02 shown in cross sectionin Figure 5. Removal of the escutcheon I02 makes accessible the rod I03which carries an enlarged head cam surface I04 on the inner side of thepanel I2. The head I04 when withdrawn as shown in Figure 4 engages oneside of the lever 39 so that when the treadle bar 56 is actuated, thelever 44 may move without moving the lever 39 thus maintaining inengagement the Wheel 48 with the roller 38 and the cable 28. With theescutcheon removed, the screw 14 is loosened and the pointer of theradio receiver dial is moved to the desired radio station. When theradio receiver has thus been tuned, the manual control is retained inposition manually and the push button is moved inwardly so that the bars59 engage the loosened cam 84 thus moving the cam to its new position.After the nism will move the tuning condenser to a predeterminedposition.

In order that there be no possibility of looking in position the wheel48 after the various push button levers have been adjusted,theescutcheon I02 is replaced thus moving inwardly the shaft I03 so thatthe head I04 no longer is in position to engage the lever 39.

Whenever a push button I6 is actuated the first action to take place isthe movement of the treadle 56. The treadle 56 acts to pull the cable orcord 64 which is attached to the lower extremity of the lever 44.Sufiicient friction is provided between the lever 44 and the lever tolift the wheel 48 away from the roller 38. This action occurs during thefirst one-sixteenth inch of travel of the push button I6. Further travelof the push button I6 causes further movement of the treadle 56 whichthereafter merely moves the lever 44 without any substantial movement ofthe lever 39.

The cams and 86 engage the cam bars 59 secured to the rotor of thetuning element to move the rotor to a selected predetermined positioncorresponding to the radio station to which the receiver is to be tuned.When the push button I6 is released the spring 53 draws the treadle backand also moves the lever 44 until the forward projection 5I engages theextremity50 of the lever 39 thereafter causing movement of the lever 39also. This brings the wheel 48 back into engagement with the roller 38and the cable 28. Due to the high ratio of drive between the manualtuning control shaft 36 and the shaft of the tuning element H, themanual control acts as a brake to retain the rotor of the tuning elementin position against any movement from extraneous causes such asvibration.

The disengagement of the manual tuning control knob during the operationof the push buttons reduces the pressure necessary to actuate the pushbuttons and also reduces the Wear on the cable 28 thus providingover-all smoother operation. The linear dial provides adequateindication spacing which is particularly desirable for tuning the radioreceiver in the higher frequency ranges. The arrangement of thelongitudinal dial together with the dial pointer provides an arrangementwherein the dial pointer may be inherently light in weight and yetprovide accurate indication by virtue of the contact with the pointerguide rail.

As heretofore described it is apparent that it is relatively easy tochange the adjustment of any one of the push buttons by removing theescutcheon plate I02 and withdrawing the locking member I03 so as toprevent movement of. the lever 39 upon actuation of a push button. Thepush button locking screw 14 is loosened so that subsequently the cam 84may be moved to the new position. The desired radio station is tuned inby actuation of the manual control knob I 4 which is held fixed by theoperator. While the manual control is thus held the push button I6 ismerely moved forwardly to orient the cam 84 to its new position. Thepush button there upon may be released and the screw I4 tightened. Thespring 88 retains the cam 84 in its new position until the screw I4 istightened, the screw thereupon acting upon the locking members "I5 sothat the cam 84 will remain fixed irrespective aware! of the forceapplied to the cam surfaces 85 and 86 when the cam bars 59 are engagedat the time that the rotor is to be moved to the new selectedpredetermined position. v

' While for the purpose of illustrating and describing the presentinvention a preferred embodiment has been shown in the drawings, it isto be understood that such disclosure does not constitute a limitationsince such variations in the instrumentalities employed and in theirarrangement are contemplated as may be commensurate with the spirit andscope of the invention set forth in the following claims.

This invention is hereby claimed as follows:

1. A radio tuning device having a push button mechanism for moving saiddevice to a selected predetermined position, a manuallyrotatable tuningcontrol for said device, cable and pulley driving means interconnectingsaid device with said control to provide a driving ratio greater H thanone therebetween, and means responsive tothe initiation of operation ofthe push button mechanism for disconnecting said cable driving meansfrom said control.

2. A radio tuning device, a push button mechanism for moving said deviceto a selectedpredetermined position, a manual tuning control for saiddevice having a driving roller, cable and pulley means normallyinterconnecting said device with said roller including means for causing1 said cable to engage said driving roller, and means actuated by saidpush button mechanism for disengaging said cable and driving roller.

3. A radio tuning device, a pushbutton. mechahism for moving said deviceto a predetermined position, a manual tuning control for said devicehaving a driving roller, cable and pulley means normally interconnectingsaid device with said roller including an idler wheel spring biased tocause said cable to engage said driving roller in driving relationthereto, and means actuated by said push button mechanism for movingsaid idler wheel out of engagement with said cable and driving roller.

4. A radio tuning device, a push button mechanism for moving said deviceto selected predetermined positions, a manual tuning control for saiddevice having a driving roller, cable and pulley means interconnectingsaid device with said driving roller to provide a driving ratio greaterthan one therebetween, an idler roller spring biased to cause said cableto engage said driving roller in driving relation, and means: actuatedby said push button mechanism for moving said idler roller out, ofengagement with said cable and driving roller thereby to disengagesaidcable and pulley means from said driving roller.

5. A radio tuning device, a push buttonmeche anisni for moving saiddevice to selected predetermined positions, a manual tuning control forsaid device having a driving roller, cable and pulley means adapted tointerconnect said device with said manualtuning control to provide adriving ratio greater than one therebetween', a shiftable shaft, anidlerwheel mounted on said shaft for causing said cable to engage saiddriving roller, and; means responsive to the actuation of said pushbutton mechanism for shifting said shaft to disengage said idler wheel,from said cable and-driving roller to render inefiective said manualtuning control.

6. A radio tuning device, a push button. mechanism for moving saiddevice to selected prede;--

8* termined positions, a manual tuning control for said device having adriving roller, cable and. pulley means adapted to interconnect saiddevice with said manual tun-i-ng control to provide a driving ratiogreater than one therebetween, an idler wheel for causing said cable toengage said driving roller, said idler wheel being mounted on ashiftable shaft and selectively operable means for maintaining saidwheel in engagement with I said cable and driving roller while said pushbutton mechanism is actuated.

'7. A radio tuning device, a push button mechanism for moving saiddevice to selected predetermined positions, a manual tuning control forsaid device having a driving roller, cable and pulleys-incans adapted tointerconnect said device with said manual tuning control, an idler wheelwhich causes said cable to engage said driving roller in drivingrelation thereto, said idler wheel being mounted on a shaft having oneend being supported by a fixed member and the other end supported by: apivoted lever, a second lever pivotally connected to saidpivoted lever,a spring for biasing said second lever to a predetermined position tocause said first lever to move said idler wheel into engagement withsaid cable and said driving roller, and means actuated by operation ofsaid push button mechanism for moving said levers against the action ofsaid spring to disengage saidcable and driving roller.

8. A radio tuning device, a push button mechanism for moving said deviceto selected predetermined positions, a manual tuning control for saiddevice having. a driving roller, cable and pulley means forinterconnecting said device for said manual. tuning control including anidler wheel for causing said cable to engage said driving, roller, saididler wheel being mounted on a shiftable shaft, a pivoted treadle'bararranged to be actuated by said push button mechanism, a connectionbetween said treadle bar and said shaft for moving said idler wheelagainst said spring biasv out of engagement with said cable and drivingroller.

9-. A radio. tuning device. having a plurality of push button actuatorsfor moving a tuning element to selected predeterminedpositions, a manualtuning control, a horizontal dial having a dial. pointer guide rail,. acable. arranged to move horizontally along said dial in the proximity ofsaid. guide rail, a pointer mounted on said rail andsecured to saidcable,v a pulley for; said cable, means connecting said pulley with themoving part: of) said tuning element, an idler pulley normally biasedagainst said cable and said manual tuningv control, a treadle bar,arrangedito be actuated by any one of, said push button. actuators, and"means interconnecting: said. treadle bar and said idler pulley" formoving said pulley away from said cable and said: tuning control;

DONALD H. MILLS.

REFERENCES CITED The following references areof. record in the file. ofthis patent:

UNITED STATES PATENTS Number Namev Date 2,153,865 Gersch Apr. 11, 19392,267,474 McGarvey Dec..23, 1941 2288;098- Marholz et al June 30, 19422,35 1, 143 Metcalfe et a1 June 13, 1944 2,372,099 McGarvey Mar. 20,1945

